


Curiosity

by rachel_exe



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alternate Universe - Merpeople, Alternate Universe - Modern Setting, Barebacking, Bottom Levi (Shingeki no Kyojin), Double Penetration, Dry Orgasm, Eren Yeager Has a Big Dick, Fisting, Fluff, Interspecies Sex, M/M, Multiple Orgasms, Overstimulation, Sea Monsters, Shameless Smut, Smut, Tentacle Sex, Tentacles, Top Eren Yeager
Language: English
Status: Completed
Published: 2020-10-25
Updated: 2020-10-25
Packaged: 2021-03-08 19:36:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 9,826
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27191836
Author URL: https://archiveofourown.org/users/rachel_exe/pseuds/rachel_exe
Summary: After months of working himself off without taking a break, Levi finally accepts Hange's offer to spend some time at their beach house to relax. The little sea town is perfect for Levi's purpose, quiet and peaceful, if only it wasn't for the monster populating its waters. Curious about the supernatural being, Levi decides to dig into it, quite not expecting things to go the way they do.
Relationships: Levi/Eren Yeager
Comments: 30
Kudos: 356





	Curiosity

**Author's Note:**

> Hello! Yes, you read the tags correctly, this fic will contain tentacles smut, so if this isn't your cup of tea, maybe don't read the fic, if you're _curious_ (hehe) about it, then welcome, I hope you enjoy the story, there actually is some plot and unexpected fluff. It took me exactly a month to write this, but I'm pretty happy with how it turned out, it definitely is something out of my comfort zone, but it was a lot of fun, and I hope you'll like it too :)

The restless sea roared under the grey sky, furious waves crashing against the sharp rocks on the shore. The treetops bent under the strong wind, and the dark clouds threatened rain at every second. Levi leaned over the steering wheel to judge whether he would make it to the house before the storm broke out or not. Moving into his new temporary place while being drenched was less than ideal, but for as much as he would have liked to drive faster, the weather was too dangerous, and he didn’t want to lose control of his vehicle.

He finally entered the sea town and followed the instructions Hange had given him to reach their house. It obviously had to be the one on top of a hill, so not only did he have to fight with the wind, but also with gravity. He cursed under his breath as he once more looked at the sky, a lighting striking in the distance. He drove up the narrow street, and after too many turns, a house appeared in his view. It was small, just one floor with a spacious front yard, but it looked out on the sea and it was far away from other buildings, which made it perfect for Levi’s purpose. 

As he came up the hill, he noticed a figure standing in front of the house. The person briskly walked to the car while Levi parked, and was ready to greet him when he turned off the engine. 

“Hello, you must be Levi,” the man said with a welcoming smile. “I’m Moblit, Hange’s childhood friend, I take care of the house when they’re not here.” 

“Hi,” Levi replied with a nod, gathering his luggage from the trunk and following the man to the house. 

“It was sunny until a few hours ago, but now it looks like we’re going to get a storm tonight,” Moblit said as he opened the front door. “You’ll be safe here, don’t worry, the house is very sturdy.” 

A comfortable warmth hugged Levi when he stepped inside. The lights were already on and as Moblit guided him to the living room, he noticed a few logs were burning in the fire place, quietly crackling as they turned to ashes. 

“As Hange suggested, I bought a few supplies so you can settle in without worrying about dinner or breakfast,” Moblit said. 

“Thank you,” Levi replied, looking around. “Hange can use their brain sometimes then.” 

Moblit smiled. “They wanted to make sure you found the house to your liking. I’ll let you settle in now, if you need anything, my number is on the agenda near the entrance, the keys to the house are there too.” 

Levi nodded. “Thank you,” he said. “You better hurry before all hell breaks loose.” 

“Yes, sometimes the waves reach the roads too, it’s not safe to be out with a weather like this.” 

After saying his goodbyes, Moblit left the house, and Levi could freely inspect the building where he’d be spending the next two weeks. 

After working himself off for months on end without breaks, Hange had forced him to take a few weeks of leave from the office, and had suggested their summer house as the perfect location. In other circumstances, Levi would have been deadly set against it, but it was already autumn and the weather less than favourable, so the chances of encountering annoying tourists were slim. The seaside town was also rather small, and the population mainly consisted of old people, so Levi was certain to find some much-needed peace there. 

He picked up his luggage and explored the house in search of the master bedroom. He walked down a corridor past the kitchen, opening two doors – the bathroom’s and a little study’s – before finding it at the end of the hallway. The room was cleaner than Levi had expected, maybe Hange had asked Moblit to clean around a bit too. Levi left his baggage there, too hungry to take care of that now, and moved back to the kitchen. 

As Moblit had told him, the fridge was full, but tired from the journey, Levi didn’t have the strength to cook anything more complicated than a simple pasta with tomato sauce. He put the water to boil, and while he waited, he took a trip to the bathroom. There too he found all the supplies he might need, and even cleaning utensils in a cabinet under the sink. Hange knew him all too well. 

His dinner was soon ready, and he sat at the small table near the window in the living room. The trees were swaying under the wind, and a few big drops of water started hitting the glass next to Levi. The sky was black, and only a few streetlamps illuminated the town, but Levi could clearly see the sea. The impetuous waves hastily crashed over the rocks, covering the shore of foamy water before retreating. Levi was certain all the inhabitants of the village were locked inside their houses, warming up by the fire or already in bed, and yet he saw someone swim in the sea. 

It was just for a few seconds, a brief instant in which a figure appeared between the waves, and then was gone, but Levi didn’t doubt it was real. He leaned forward to better see outside, but the person was gone, either washed away by the waves or under water. He furrowed his brows. Who could be so crazy to go swimming in a night like this? But then Hange’s words came to his mind. 

_There is said to be a monster in the waters of the village._

Levi scoffed. A monster? What a load of bullshit. It was more likely that the dim lights and tiredness from the journey had made him see things, the sea was raging after all, so it was almost impossible to see what was moving inside it. Hange could have also been making fun of him to make his stay more eventful, so he was going to ask Moblit the following day, sure he would be able to assure him of the absurdity of the rumour. 

He finished his dinner watching the storm getting stronger, and then sat on the sofa by the fire. He put two more logs on it, and after making himself a hot cup of tea, he took a book to read before bed. It was the first time in a long while that he had been able to do that, he had been focusing on his work too much lately, forgetting to make time for himself. 

He spent an hour on the sofa, but when he realised he was dozing off more than he was reading, he headed to the bedroom. As he walked by the window, his eyes instinctively went to the sea. Despite his disbelief, curiosity had planted its seed in his brain, and he kept wondering about the figure he had seen. He shook his head, what was he even thinking about? He tore his gaze away from the raging waves and went to bed. 

The sun was shining in the sky when Levi woke up the following day. No signs of the storm were left, only the leaves scattered around and the wet sand that was slowly drying. It was too cold to eat at the table outside, so Levi had breakfast sat at the same table of the evening before, eyes once more on the sea. Now that it was daylight and the waves were calm, he could perfectly see the blue expanse outside, and no one was swimming in it. 

His curious side was disappointed, but his rational one was quick to discard the feeling. He didn’t come here to solve a mystery, if there even was one. He had decided to take some weeks off to relax and make some time for himself, so after breakfast, he decided to walk around a little, explore the town, and forget all about work, unknown creatures, and all sorts of mysteries. 

The air outside was crisp, and the smell of the sea clearly reached the area where Levi was. With his hands deep inside the pockets of his jacket, Levi started walking down the hill. The road was wet and slippery, so he had to walk with his head down not to fall, but once he reached the even ground, he could take in the view around him. 

The town’s buildings mostly consisted of old houses and little shops where people bought their supplies. Many of those shops sold equipment related to the sea or fishing as was to be expected, but Levi wondered how much they were selling now that the tourists weren’t there. It was in one of those shops that Levi saw Moblit behind the counter with a book open in fort of him while a customer was looking around. 

Levi’s curiosity prompted him to go inside, so without thinking too much about it, he opened the door to the shop. He had to get to the bottom of the mystery to appease his mind once and for all. The little bell above the door chimed, and Moblit raised his head, welcoming him with a warm smile. 

“Good morning, Levi, how was your first night at the house?” 

“Quiet, which is exactly what I wanted,” Levi said, going near the counter. 

“I’m glad to hear that,” Moblit replied. “Any plans for today?” 

“Not really, I’ll just wander around a bit.” 

“You should definitely visit the natural museum, it’s small, but it has some really interesting things.” 

“I’ll keep that in mind.” Levi looked around the shop. “Did the storm cause damages yesterday?” 

“Just a few broken branches and some bent signs, nothing we haven’t seen before. Was the house okay?” 

“Yes, it was perfect, no damages there,” Levi said, fixing his gaze on Moblit. “Even though, I thought I saw a figure swim in the sea yesterday during the storm, it must have been just my imagination, right?” 

Moblit awkwardly smiled, humming uncomfortably, but before he could open his mouth, the only costumer in the shop slammed a can of fishing worms on the counter. 

“It was that damn monster,” the old man said in a harsh tone. “It’s the only one crazy enough to go swimming when the sea is like that.” 

“Monster?” Levi raised an eyebrow while a hint of excitement tugged at his gut. 

“Yes, people keep seeing weird shapes in the sea during the night,” Moblit explained. “No one dares to go near the beach in the evening, and even when the sun is out, people pick up their pace if they have to cross the beach.” 

“That damn monster is eating all the fish too,” the other man said. “I can barely catch any nowadays.” 

“When did you start seeing this monster?” Levi asked. 

“Nobody really saw it, but the unusual shapes in the water have first appeared a couple of months ago,” Moblit replied. “Thankfully, it didn’t ruin the town’s reputation too much, so tourists came as always, but things might change next year if the rumour spreads.” 

“You might get more of those crazy mystery hunters, though,” Levi pointed out. 

“I don’t want my town to turn into some kind of spooky attraction for those idiots,” the old man exclaimed. “That monster better leave before we go hunt it.” 

Moblit smiled uncomfortably again while Levi pondered on the piece of news. A monster in such a peaceful town? He had to admit his interest was piqued now. 

The old man paid for his worms and then left, still mumbling something about the monster. 

“People don’t like the idea of having such a scary neighbour,” Moblit explained once they were alone again. 

“So Hange wasn’t shitting when they said there was a mysterious creature in the waters here,” Levi said. “Have you ever seen it?” 

“No, and I hope I never will.” 

Levi hummed, but he couldn’t say he agreed with him. Curiosity had already had the best of him. 

Once outside, the first thing Levi did was to go down to the beach. As Moblit had said, all the people he met on his way there were in a hurry, throwing glances behind them while they looked for safety inside the village. Levi didn’t see anything suspicious from afar, so he made his way on the wet sand until he reached the water. 

The waves were gentle, and the sunrays sparkled on their surface. No boats were out in the open, but a few people were fishing on the rocks. Everything seemed peaceful, and no unexpected sightings came to disrupt the calm morning. The sound of the waves was so soothing that Levi decided to hang around there for a while. He found a clean spot to sit down on and then contemplated the sea in silence. 

Worries from work started coming into his mind together with all the flaws in his life. He had been spending all his time at the office to forget about his empty apartment, about the silence that waited for him at home. It had been years since he had gotten a lover and, sadly, years since he had gotten laid. Maybe he should start looking for someone when he got back, but he immediately shoved that thought to the back of his mind. He didn’t have time to waste on that, he had a business to run. 

He spent most of the day wandering around, walking up and down the beach, and then exploring the narrow streets of the town. It didn’t take him long before mapping out the entire village, or at least anything even remotely interesting, so he headed back home as the sun started to set. Before dinner, he took a shower and then settled in the kitchen where he prepared some food for dinner. 

When everything was ready, he decided to eat at the table outside. It was getting colder, and the sun was rapidly setting, but the sea kept demanding Levi’s attention, and he had no power to fight the urge to look for the creature. He turned on the light outside and ate his dinner while keeping an eye on the water. Nothing unusual made him jump on his seat, but the sight and sounds of the regular waves were so relaxing, Levi stayed outside even when his food was all gone. 

The sun had set, and the streetlamps were lighting up the view when a shadow in the sea caught Levi’s attention. His eyes opened wide and before he knew it, he was running to the fence, leaning over it as he scrutinised the water in front of him. He had seen something, he was certain of it this time, but he didn’t see the shadow again no matter how long he stared. 

Disappointed, he went to sit down again, but an excited fire had started to burn inside him, one that had been dormant for too long. 

The following day, Levi headed down to the beach early in the morning. The sun had just risen, and the crisp autumn air smelled of the sea. No one else had had the same idea as him, on the contrary, people threw him concerned glances when they saw him walking towards the sand. Levi shrugged it off, he couldn’t understand what they were so scared of. Was an unidentified creature eating their fish enough to make people shit their pants? 

It certainly wasn’t for Levi, who approached the sea with scrutinising eyes, trying to catch even the slightest of suspicious movements under the water, but failing to see anything out of the ordinary. He had brought a towel with him to sit on, so after laying it on the ground, he sat down with his legs crossed and his gaze on the horizon. He had brought a book to read too, but curiosity was once again having the best of him, shifting all of his attention to the expanse in front of him. 

He stayed at the beach for the entire morning, keeping an eye on the sea while he read or just got lost in thought. A few fishermen’s boats crossed the sea in front of him, but the other inhabitants of the town remained far away from the beach. Levi couldn’t understand what their fear was, he hadn’t seen anything worthy of attention, the water was still for as far as the eye could see. 

Levi wondered if he had come at the wrong time. The weird shape he had seen before had always appeared when the sun was down, so maybe he just needed to head to the beach at night, when the supposed creature would go hunting for food. 

A chill ran up his spine at the thought. The locals said that the monster had eaten all their fish, but that wasn’t enough to prove that it only fed on animals. Levi himself could be considered a prey. 

The idea only put a grin on Levi’s face. 

With the intention of going back in the evening, Levi left the sea and went back home. Once there, he had some food and then prepared a hot bath; after spending all that time outside, he was cold to the bone. The warm water covered him like an embrace, and he immediately relaxed, closing his eyes and letting his body rest. 

He had been soaking in the water for ten minutes, a pleasant slumber slowly falling over him, when his phone rang. He peered his eyes open, and checked the device he had placed on the floor next to the bathtub. He huffed at seeing who was calling him, but he picked up nonetheless. 

“What do you want, Hange?” 

“Hello to you too, I see the holiday isn’t making you less grumpy,” a chirpy voice said from the other side of the line. 

“I’m in the middle of taking a bath, so this better be important,” Levi retorted. 

“You’re in full holiday mode, aren’t you?” Hange replied. “I wanted to see how you were doing, do you like the place?” 

“It’s not bad,” Levi replied. “The house was surprisingly clean, did you ask your friend to tidy up before I came?” 

“Of course, I knew you’d have spent the entire holiday cleaning otherwise.” 

“It was that dirty, wasn’t it?” Levi grimaced. 

“You don’t need to worry about it,” Hange shushed him. “So, what have you been up to so far?” 

“Nothing much, I’ve just wandered around a bit. People here are really scared of that monster, aren’t they?” 

“Wait, there’s really a monster?” Hange exclaimed, surprised. “I thought Moblit was joking when he told me about it.” 

“And you told me about it to scare me, didn’t you?” Levi clicked his tongue. “Yes, there is a fucking monster here, or at least people think there is, they don’t go near the beach, they even think it’s eating all their fish.” 

“What? Are you serious? Damn, I wish I was there with you,” Hange replied with a disappointed tone. “Have you seen it?” 

Levi worried his bottom lip before replying, “Maybe.” 

“Don’t leave me hanging like this!” 

“I don’t even know what I saw, all hell had come loose the day I arrived, and I saw a weird shape swimming in the sea, so I don’t know if it was the monster or not.” 

“But you’re looking into it, aren’t you?” Levi could hear the grin in Hange’s voice. 

“I have nothing better to do,” Levi shrugged. 

“A few days of holiday, and you’re already finding new hobbies.” 

“Yes, I’ll start a ghost hunting agency when I come back,” Levi ironically said, rolling his eyes. 

“That could be a good idea, we might even set one up there at my place, someone has to catch that monster.” 

“We?” 

“Yes, I’m not missing this bus, we could become monster hunters or something like this.” 

“Since you’re starting to spout nonsense, I’m hanging up, the water is getting colder.” 

“Never as cold as you,” Hange protested. “Keep me updated on that monster.” 

“Will not do, bye.” 

Levi hung up and placed the phone on the ground again before finishing his bath. 

He waited with trepidation for the sun to set. He had gotten everything ready; a flashlight, a warm coat, a blanket to sit on, and a thermos of tea to keep him awake. He still had no idea for how long he’d have to wait nor what he was going to do if he saw the monster, he hadn’t thought that far ahead, for once he just wanted to go with his gut and see how things would end up. 

When it was dark enough, he left the house again. No one was around, it was like all the inhabitants had abandoned the town and Levi was the only one left. He made his way through the silent streets and followed the sound of the waves, the streetlamp giving the path a yellow hue. Once he reached the sand, he turned on his flashlight, and walked up to the shore. He flashed his light for as far as it could go, but he didn’t see anything in particular, so he laid his blanket down and sat on it to wait. 

His eyes never left the water in front of him, he closely followed every movement of the waves, listening to their rhythmic sound to catch anything out of the ordinary. He had to be patient for over an hour to get the result he wanted. He was mindlessly flashing his light over the sea, turning it on and off, when a swift movement caught his eyes. He pointed his light towards it, standing up and approaching the sea. There was an almost inaudible splash, and in the far distance, Levi thought he could see a head. 

His heart picked up its beat at the sight. He had found what he was looking for, or at least hoped he had. He didn’t have enough time to prove it, however, as the apparent head disappeared immediately after, and no matter how much he waited, it didn’t appear again. 

After the episode, Levi decided to go home. He was disappointed his encounter had been so short, but he had no doubts he had met the so-called monster, it had to be that creature. Frozen for the excitement of his discovery, he hadn’t even had the time to say or do something, and the creature had gone away, but he wasn’t going to be caught off guard the next time. 

The following days, Levi kept going to the beach in the morning and evening. It had become almost an obsession, an itch he wasn’t able to scratch, and his curiosity was having the best of him. In such a secluded town there wasn’t much to do anyway, and chasing this creature lit a fire inside Levi, one that his monotonous desk job had put out many years ago. He wanted to experience something new, find some kind of adventure to embark on, and this was his best chance to do so. 

It was always during his night watch that he saw the creature. He couldn’t be fully sure of it, he just heard a splash and what seemed like a head appeared in the far distance, but he wanted to believe it was the creature. No matter how many evenings he spent there, he never said anything. What could he say to a creature that probably didn’t even speak his language? There was nothing he wanted to communicate anyway, no desire to subjugate or “civilise” the foreign species, so he just witnessed the supernatural event happening in front of his eyes. 

As the days went by, the creature slowly started to approach him. At first Levi had thought he was just imagining it, it was too dark to be certain of anything, but one evening, he saw eyes glow in the dark, a deep teal that pierced right through him. In that moment he didn’t feel scared or in danger, instead, he was excited, he forgot all about his mundane life, all about his empty bed and void house, and just wished to get closer to the creature. 

The thought was short lived as the head disappeared soon after. He waited for a few minutes as per usual, but when the figure didn’t surface again, he got ready to leave. He stood up and was packing his things when a louder and much closer splash reached his ears. The creature was nearer this time, so close that he could see its hair reaching its shoulders. The euphoria for the close encounter lasted only a few seconds as, without notice, the creature’s arm appeared from underneath the water and a fish hit Levi right in the chest. 

“What the fuck?” he hissed, looking at the animal desperately trying to survive on his feet. 

He looked up again, but was hit by another fresh fish. The cold water soaked his coat, and the animal’s smell was already sticking to his clothes. He had barely the time to register all of that, that a fish after another started hitting him everywhere, from his trousers to his chest and one even his face. 

“What the fuck are you doing?” he yelled again. “If you didn’t want me here, you just needed to say so, you fucker.” He grabbed a fish from the ground and threw it back into the water. “Here, take this. Do you like being hit by a fucking fish?” 

The animal ended up somewhere in the dark water, and the creature stopped his assault. Levi wished there was some source of light to better see the creature, his flashlight wasn’t doing much unfortunately, but he was fairly certain the figure was cocking his head to the side. 

“You don’t like it, do you?” Levi exclaimed. He took another fish and threw it in the water as well. 

There was a moment of silence where the two looked at each other and then the creature’s arm appeared again, and a fish flew right into Levi’s hair. 

“You asked for this,” Levi said through gritted teeth before sending the fish right back into the sea. 

For a few seconds, dead and alive fish flew from the sea to the shore and back, never failing to hit some part of Levi. The raven’s hands were stinky and wet, covered in sand mixed with fish intestines, but he couldn’t bring himself to leave. He was drawn to the creature, and this seemed like the only way it knew how to communicate. 

Only when the fish started arriving in pieces rather than entirely did he finally stop. 

“Fine, I give up, you win, okay?” he yelled. “You can keep all that disgusting fish for yourself, I’m going to take a shower.” 

He crouched to gather up all his stuff, and one final fish hit him right in the face. He glared in the direction of the creature, he didn’t know if it was able to see in the darkness, but he hoped he could feel the murderous aura he was exuding. 

“You fucking asshole,” he hissed. He stood up again with his things under his arm. “Just go fuck yourself.” 

He showed the creature his middle finger before turning around and heading back home. There was a louder splash as he left, but Levi didn’t turn around, he had had enough of the creature for a day. 

Once home, Levi took a shower, furiously scrubbing himself to wash away the smell of slime and fish, but despite how his encounter with the supernatural being had gone, he couldn’t help but grin to himself. He had been able to make a first contact, he had proven that the monster really existed. Now he only had to see it up close. 

The following day he woke up at the crack of dawn. He had been thinking about the encounter with the creature for the entire night, tossing and turning in bed while thousands of questions crossed his mind, wondering what to do next and what to expect, but with the end of his holiday so close, he was tired of waiting. He needed answers immediately. 

After a quick breakfast, he put a few essential things in a backpack and headed out. He briskly walked down the streets, determined, and reached Moblit’s shop a few minutes after it had opened. There were no costumers yet, but even if there had been, Levi’s resolve wouldn’t have weakened. 

“Hi, Levi,” the man greeted him as soon as he stepped inside. “How are you doing? Do you need something?” 

“Hi,” Levi replied, walking up to the counter. “I saw you rent gear for scuba diving, don’t you?” 

“I do. Not many people ask for it at this time of the year, but I still keep a few oxygen tanks and suits, why? Do you plan on going out in the sea?” 

“Yes, actually.” Levi nodded. “I used to go scuba diving pretty often a few years ago, and I’d like to do it again while I’m here.” 

“Aren’t you afraid of the monster?” Moblit joked, but behind his playful words, Levi could sense a hint of worry. 

“No, it’s all bullshit.” Levi shrugged. “So, can you give me the stuff?” 

“Sure!” 

In a few minutes, Levi was all dressed up with a tight black scuba diving suit and two full oxygen tanks. Moblit lent him a boat as well, insisting Levi asked someone to go with him in case something bad happened, but Levi refused. He knew what he was doing and didn’t want anyone to interfere if he found the marine creature. 

From the little dock near the beach, Levi started his journey into deeper waters. He didn’t have a clear idea of where to go, he was just going to wander around a bit, keeping an eye out for anything suspicious. He crossed over the line of the horizon and little by little, the town started disappearing from his view. He kept his gaze in front of him, searching the water below him and looking around until a protuberance caught his attention. 

It was a round shape in the middle of nothing that grew bigger as he approached it. He soon discovered it was a little island with tall trees and surrounded by rocks. When telling him a bit about the town, Moblit had mentioned the island as a place where fishermen often stopped by while coming in and out of the village. Unfortunately, the man had forgotten to mention where the dock the fishermen used was. Levi supposed there was a little alcove or a path to follow to get to the heart of the island, but he couldn’t find it and didn’t have time to waste looking for it. 

He stopped his boat near the reef, lowering the anchor and throwing the marker buoy that indicated someone was down in the water. He wore the mask and oxygen tanks, giving one last glance around before diving. Since he couldn’t get onto the island, he was going to see what was under it. 

He swam around, diving deeper and deeper. He met some fish on his way down, different kinds of animals that peacefully went from one side of the sea to the other. Thankfully, he didn’t see any kind of dangerous animals, so he circled around the island, checking the rocks underneath him and trying to find anything even remotely out of place. 

The island was rather small, so it didn’t take him long to reach the middle of it. At first, nothing caught his eye as he looked around, but upon closer inspection, he noted a crack on the rock under the island. He swam towards it, bubbles coming to life next to him every time he breathed. When he was close to the crack, he turned on the flashlight he had brought and checked the area before him. 

There was a long tunnel, narrow, but wide enough for Levi to swim into. He shone the light on the walls of the crack, but he couldn’t see anything out of the ordinary. There might have been dangerous animals hiding in some holes, but at that point he was too curious to turn back, so keeping the light on, he swam forward. 

The tunnel went on for a while, the cold water sending chills down Levi’s spine. It wasn’t the time to give up, though, and as he swam with his heart beating faster, Levi couldn’t help but wonder what he was going to find. An increasing excitement directed his movements as he reached the end of the crack. At first sight, it seemed like the tunnel was going to end there, but as Levi approached the wall, a faint light came from above him. He looked up and realised there was an opening over his head, so he moved towards it. 

When he came out of the water, he found himself in a spacious opening with the walls made of the same rocks as the ones around the island. Only on the opposite side of the little pool there was a little entrance, but only a faint light came from it. Levi pulled himself up on the ground, removing his fins and oxygen tanks before placing them near the water. 

There were no signs of human presence in the cave. As he looked around, he couldn’t find anything suspicious, only a few puddles here and there and some smaller rocks scattered around. Determined to get to the bottom of the story, he walked around, his bare feet leaving prints on the thin layer of sand on the ground. Looking closely, he noticed bigger footprints here and there, but the sand was so scarce and the traces so faint that he couldn’t be sure if they were fresh or not. 

He kept walking towards what seemed to be the entrance of the cave but stopped when he a figure appeared from around the corner. His heart pounded for the surprise and excitement. Could he have found the creature? Judging by the man’s appearance he couldn’t be sure. He looked like a normal twenty-year-old with brown hair that reached his shoulders and eyes of the colour of the sea under the sun. Levi was stunned by his beauty, but he was even more surprised when he realised the man was naked. 

Every part of his body was toned, and Levi couldn’t stop a shiver of arousal from running up his spine as his eyes landed on the man’s cock in full display. 

“Yes?” the boy spoke, and his deep voice captivated Levi even more. 

Levi was at a loss for words. He hadn’t thought he’d meet someone else on the island, let alone someone as attractive as the man in front of him, so after gaping in vain a few times, he said the first thing that came to his mind. 

“What are you doing here?” 

“I live here,” the man replied as if it was the most obvious thing on Earth. 

“Here?” Levi raised an eyebrow. 

“Yes.” 

“Why?” 

“I like it.” 

Levi narrowed his eyes, trying to understand what was going on with that person. His answers were so direct and honest that Levi didn’t doubt he was telling the truth, but he hadn’t even questioned Levi’s presence there, supposedly in his home. Wasn’t he surprised or scared of it? 

“Have you seen anything suspicious around here?” Levi then asked. 

The man cocked his head to the side. “Suspicious?” 

“People believe there’s a monster in these waters.” 

A sly smirk appeared on the boy’s mouth. “Is that why you’re here?” He walked up to Levi, closing the distance between them in just a few strokes. “Did you come here to find me?” 

His eyes were gluing Levi to the spot, so mesmerising and magnetic. There was something wild in them, something you’d find in an untamed animal looking at its prey, and that flame made Levi shiver in arousal. He was sure he had found the creature, he had suspected it from the moment they had met, and now that they finally were face to face, he wasn’t going to get to bottom of it. 

“I did,” he replied, keeping his gaze on the man. 

“You’re a brave one.” 

“Is this supposed to be a threat?” Levi crossed his arms over his chest, heart pounding. 

“Take it as a compliment,” the boy smirked. “I have offered you food already after all.” 

“Food? Is that why you hit me right in the face with those fucking fish?” 

“Offering food is a courting ritual in my culture.” 

“I guess we have different concepts of ‘offering’,” Levi scoffed. “And courting ritual? What the fuck are you on about?” 

“I can smell human’s pheromones,” the boy replied with a cunning light in his eyes. “I could smell your interest, your loneliness, your desire, when you were at the beach.” 

Levi huffed. “Bullshit.” 

The boy grinned and his hot breath ghosted over Levi’s face as he whispered in his ear, “Do you want to see my true form?” 

Levi met his gaze. He had come all this way, driven by his curiosity, it would have been dumb of him to reject the offer now that he was there. He had no reason to believe the creature was an actual threat to him unless killing his partners was part of his courting ritual. 

He nodded, a brief movement of the head, almost detached, but his eyes were full of expectancy and desire. He didn’t tear his gaze away as the man moved back a bit and his body started changing. His ears got slimmer and longer, the tips pointy and sharp. He smiled, showing his now sharp canines, but what surprised Levi the most were the tentacles that started appearing from somewhere on his back. They were of a dark red with a lighter underside and floated in mid-air as if unable to stay still. Looking closely, Levi noticed even the creature’s cock got bigger and of the same reddish colour as the tentacles, its veins clearly visible. 

“I can’t fully change when I’m out of water,” the boy said in an even more attractive voice. “I need the legs to walk, and I can’t breathe with my gills.” 

Levi was speechless, he didn’t know how to react nor how to process what was happening before him. He had just met a supernatural creature, one that lived under water most of the times, and whose species had been populating the oceans without him knowing probably for centuries, leading its own life undisturbed. He had so many questions, so many feelings coursing through him; fear, surprise, excitement, attraction. The boy was even more beautiful than before, his eyes of a darker teal, and his features sharper but more mesmerising. 

As he silently stared at the creature, one of his tentacles slowly made its way towards him, wrapping around his thigh. 

“What are you doing?” he hissed, trying to take a step backwards. 

“My senses are even sharper when I’m in this form.” The boy moved closer again, leaning down to whisper in Levi’s ear, “I could smell your arousal from miles away.” 

Levi opened his mouth to contradict him, but the words died on his tongue. He was too intrigued and drawn to the creature to deny it, his tentacle so close to his crotch that his cock was starting to tent the swimsuit. 

“I know you want to,” the boy said while his limb reached Levi’s ass. “Just let go.” 

The tentacle pressed between Levi’s cheeks, firm and strong, and any hesitance Levi had felt until now got replaced by an increasing desire. 

“What should I call you?” he murmured. 

“Eren.” 

“I’m Levi,” he replied, closing the distance between them once more. 

Eren wrapped another tentacle around him, reaching his ass again. Levi held onto his shoulders, knees already weak and cock twitching while the fabric of the swimsuit got torn apart and the tentacles caressed his skin. It was a strange sensation, Eren’s limbs were smooth and slick, leaving a wet trace behind them, but they were also warm and soothing, stroking his ass and spreading his cheeks open. 

“You like it here?” Eren said in a velvety voice while one of his tentacles pressed on Levi’s hole. 

Levi tightened his grip on his shoulders, repressing a moan while a shot of arousal ran down his spine. “Yes.” 

“I can smell it,” Eren grinned. 

Levi opened his mouth to protest, but his words turned into a gasp when Eren slid his tentacle inside. It went in smoothly, stretching him just enough to be pleasurable without being painful. Levi immediately clenched around him, body shaken by waves of lust. 

Eren kissed his neck, grazing his sharp teeth over his skin while he pushed the tentacle further inside. Levi yelped as his hole stretched wider, and pressed his face against Eren’s neck. The creature was way taller than him, so he had to stand on his tiptoes while his knees threatened to give in at any moment. When Eren thrust his tentacle in and out again, Levi’s legs shook so hard that he lost his balance and had to hang onto Eren not to fall down. 

Eren took him in his arms and slowly lowered him on the ground, pressing his back on the sand while hovering over him. His tentacle was still moving inside of Levi, going deeper and deeper when he leaned down to kiss his mouth. His lips were soft and warm, and Levi got lost in the kiss. Eren tasted good too, so good that he couldn’t help himself from rolling his tongue inside his mouth and licking his walls, intoxicated by the scent invading his nostrils. 

As their tongues tangled, more tentacles travelled up Levi’s body, tearing apart the swimsuit and revealing Levi’s chest and cock. Eren thrust deeper inside Levi while two of his tentacles moved up to tease Levi’s nipples. Levi moaned at the feeling, all air leaving his lungs while his cock twitched. He had already gotten used to the feeling of Eren’s supernatural limbs on him, touching him everywhere and bringing pleasure to every part of his body. 

Eren thrust his tentacle deeper inside and rubbed Levi’s walls until he found Levi’s sweet spot. Their kiss broke, and Levi’s loud moan echoed in the cave. Eren smirked and kept pressing on that same spot while rubbing Levi’s nipples. Levi was gasping for air, clutching Eren’s hair while he tried to get a grip on reality. All he knew in that moment was pleasure and lust, a deep heat surging through his body and overtaking him. 

“Eren,” he cried out, closing his eyes shut. 

Eren replied by kissing him, drinking every one of his moans as his hands took hold of his hips. He pulled his tentacle away, leaving just the tip inside while his wet cock teased Levi’s hole. Levi groaned at the anticipated pleasure and pressed down on him, holding him close in his arms. After teasing him some more, Eren finally pushed inside, and his cock stretched Levi even wider. He felt his length pulsating as it slid inside, hotter than his tentacles and much thicker. Levi clenched around him, taking all of him inside until he was so full he couldn’t think of anything else. 

“Eren.” Levi gasped for air. “Fuck me, c’mon.” 

“You like this?” the creature rasped. “You keep sucking me in.” 

As if to prove his point, Eren slowly rolled his hips. Levi groaned, throwing his head backwards as more heat coursed through him. Eren repeated the movement and teased Levi’s nipples again with his tentacles. His touch was everywhere on Levi, overwhelming all his senses, taking him to levels of pleasure never felt before. He pressed his lips on Levi again, but the kiss lasted only a few seconds because Levi loudly gasped when he felt Eren’s tentacle stretch his hole again. 

It inched inside, slowly but steadily, thrusting in an out, stretching him wider and wider. He saw stars behind his closed eyelids while his cock was leaking precum on his chest. He was struggling to breathe, air refusing to fill his lungs as more and more moans left his mouth. Eren kissed his neck, his sharp teeth leaving marks on the skin. His hips never stopped and neither did his tentacles, touching Levi’s chest, his ass, and teasing his cock. 

“E-Eren,” Levi breathed out, peering his eyes open. 

A wild light was in the creature’s eyes, lust and desire shining in the deep teal. He smirked when he noticed Levi was looking at him and thrust his tentacle all the way inside together with his cock. A broken cry left Levi’s throat and a scorching wave of pleasure coursed through his body. His length was so hard it was painful, precum oozing from the tip. Eren pressed his tentacle on Levi’s prostate, hitting it with his cock as well, and Levi couldn’t stop himself from coming all over himself. 

Eren massaged his prostate as he came and kept doing it even afterwards, when Levi was empty and too sensitive. He whimpered, fighting to get some air, still so full he couldn’t properly breathe. 

“You got even hotter inside,” Eren mumbled in his ear. “Such a perfect human.” 

He ran his tongue over Levi’s neck and bit his earlobe. His tentacle had stopped pressing down on Levi’s prostate, but his hips were still moving in shallow thrusts, slowly fucking Levi again as the raven came down from his high. Levi groaned in discomfort, still too sensitive for whatever Eren wanted to do, but the fresh memory of the absolute bliss that had overtaken his body mere seconds before made him endure it. He took Eren down for a kiss, letting him roll his tongue inside his mouth, teeth dangerously sharp. 

As they kissed, Eren started moving faster, cock and tentacle going in and out of Levi at the same time. A muffled moan came from Levi’s throat, but the discomfort soon left its place to pleasure again, and his length got harder the faster Eren thrust inside him. He twisted Eren’s hair between his fingers and met his hips with the same eagerness. Their tongues moved together in a passionate dance, tasting and licking, drinking each other’s sounds as they got lost in pleasure. 

When the kiss eventually broke, Levi noticed a needy expression on Eren’s face, a franticness that wasn’t there before, but that turned him on even more. His sharp features were morphed by lust, and he was fucking Levi without restraint. His tentacles were always teasing parts of Levi’s body, his cock, his nipples, but this time one of them snuck up to his mouth and made its way past his lips. 

Levi was surprised at first, unsure about the wet and slimy texture, but when he realised Eren too was gaining pleasure from it, he decided to go along with him. He licked the red limb, coating it in saliva before sucking it. Eren shuddered at the sensation, eyelids partially closing while a low growl left his lips. He looked even more beautiful and feral like this, a vision that made Levi’s hole twitch. He kept working on Eren’s tentacle until drool was dripping down his chin and he was starting to forget how it felt to have his mouth empty. 

The tentacle inside his hole focused again on Levi’s sweet spot, hitting it together with his cock. Levi gasped, almost chocking on the limb in his mouth while his lungs burnt. Eren moved his tentacle away, leaving Levi to fight for air and leaned down to kiss Levi’s chest, running his tongue on it and licking away the drying cum. He travelled up to bite Levi’s nipple as he thrust inside. So close to his orgasm again, Levi slid a hand between their bodies and wrapped it around his cock, sighing in relief when his fingers touched it, but Eren smacked it away and replaced it with one of his tentacles. 

“I-,” was all Levi could say as his eyes closed and he came again, covering Eren’s limb with his cum. 

Eren groaned, fucking him harder and only when Levi was spent, cock soft, did he come as well, painting Levi’s insides with his hot come. 

Levi was too tired to move, too tired to even open his eyes, so he lay still as Eren pulled away, leaving him so empty it felt unnatural. His body felt lighter than ever, it was like he had ascended to another dimension full of pure bliss and satisfaction. He was spent but sated, this had been the best sex of his life. He had never been so proud of himself for following his curiosity. 

After a few minutes of silence, Eren took him in his arms, pulling one of Levi’s legs over his lap and spreading Levi’s ass cheeks again. 

“My semen is spilling,” he said in Levi’s ear, his voice raw and still with a hint of lust. 

Levi opened his eyes to meet his gaze. “Whose fault do you think it is?” 

“Mine.” The way he said it, so confident and proud with a hint of possessiveness, made Levi shudder. Eren could come inside of him any day of the week, and he wouldn’t care one bit. “I’ll help.” 

Before Levi could understand what Eren was saying, the supernatural creature moved his hand between his cheeks and pushed his fingers inside. Levi bit his bottom lip, holding onto Eren’s shoulders for dear life. 

“You’re so stretched,” Eren whispered in his ear. “I can fit my whole fist inside you.” 

Eren closed his palm and true to his words, his entire hand entered Levi’s slick hole. The substance on his tentacles had covered Levi’s whole ass in something wet and slippery, and Eren’s come was oozing from it, so Eren’s fist had no troubles going inside. Levi had no strength left, he felt boneless and completely at Eren’s mercy, but he was loving every second of it. 

Eren’s fist inside him felt too good for words, and his hole kept clenching around his arm, cock hard yet again. He was panting hard, moans and broken cries leaving his mouth whenever Eren abused of his prostate. He didn’t know how he was so into it, but everything Eren did turned him on more and more, from the way his hand was thrusting inside to the little breaths fanning over his ear, Eren was able to turn him into a panting mess in a matter of seconds every time. 

Trying to get some friction, he rutted his hips against Eren, realising only then that the creature was hard too. He glanced downwards towards their joined hips, and a low groan came from his throat at the sight. Some parts of Eren’s body were still in their supernatural form, so his hard cock was still bright red and covered in thick, pulsating veins. 

He couldn’t help but move a hand down to feel Eren’s throbbing cock in his palm. When he wrapped his fingers around it, Eren growled, thrusting his fist harder, but he didn’t protest, and Levi started stroking him as best as he could. He couldn’t focus much on what he was doing, Eren’s touch was too distracting and his vision blurred more often than not, but he did register that Eren was hotter than average, he could feel the trace of his veins with every stroke, and was surprised that his fingers could barely touch when he had closed them around him. 

He wondered how it would feel to have Eren in his mouth, throbbing and hard, heavy on his tongue and filling him as he had done with his ass. If he had had any strength left, he would have sucked Eren off, but he could hardly move his hand, and after a while he gave up on it completely, not enough strength left in his body. Eren noticed he had given up on taking him to his orgasm again, so he wrapped one of his tentacles around their cocks and continued from where Levi had left off. 

“Eren,” Levi moaned, closing his eyes as he neared the edge. 

Eren was hitting his overly sensitive prostate, and the heat emanating from his cock was engulfing his own. His body was on fire, overstimulated to the point he was going to pass out if he didn’t come any time soon. He heard Eren growl in pleasure too, but at that point, he wasn’t sure of anything that was happing outside of his body, so Eren’s lips caught him off guard when they pressed over his mouth. 

Levi did his best to reply to the kiss, Eren still tasted incredible and his lips were soft in contrast with his teeth. They pulled apart soon after when a whimper forced its way out of Levi. 

“Eren,” he cried out, cock and prostate getting abused. 

“Levi,” Eren growled, low and raw with lust, a hint of desperation in it too, and that was enough for Levi. 

His body trembled, orgasm washing over him, but nothing came out from his cock; after reaching his high for the third time in a row, he came completely dry. Eren’s tentacle kept working on them for a few more seconds until Eren came too, covering them both in his thick come. Eren eventually pulled his fist out and Levi slumped on him, too far gone to even open his eyes, and fell into a deep slumber with the feeling of Eren’s arms around him. 

When he woke up, water was washing around him, cool against his heated skin. He blinked a few times, trying to remember where he was and what he was doing, but his thought process was interrupted when he realised he wasn’t sinking and that someone was holding him up. He raised his head and met Eren’s questioning gaze, staring right at him with a hint of worry in his breath-taking eyes. 

“You okay?” the creature asked in a low voice. 

“I think,” Levi replied. His throat felt awfully dry, and he was still tired despite the little nap. He tried to move around to stand on his own but stopped when he realised he was fully naked. “Where’s my swimsuit?” 

“Over there.” Eren indicated a place somewhere behind them. “It was torn apart, and I don’t understand the need for clothes anyway.” 

“I figured,” Levi muttered. 

He looked around and noticed Eren was holding them up in the little pool that was the entrance to the cavern. Eren’s tentacles were moving under the water, keeping them afloat. 

“I cleaned you,” Eren said, getting Levi’s attention again. 

Levi nodded, checking himself before looking back at Eren. “You still haven’t told me who you are.” 

“I’m Eren.” 

Levi scoffed. “I know that. What are you?” 

“I’m part of a tribe of different merpeople that live under water,” Eren explained. “We have some human features, but also fish ones.” 

“You’re not all the same?” 

“Are you humans all the same?” Eren smiled. 

“Point taken,” Levi admitted. “Why are you here?” 

“I wanted to see what was outside my village,” Eren said. “I’ve always been fascinated by humans too, I wanted to know more about you.” 

“Why not go into some towns in your human form?” 

“I can’t stay like that for too long, my body needs water to survive, so I’ve been watching you from afar.” 

“You’ve been scaring people.” 

“I never meant to.” 

Levi hummed, convinced by Eren’s story, but there was still something running around in his head. “Is that why you fucked me? Because you were curious?” 

“Isn’t mating part of humans’ wooing rituals?” Eren furrowed his brows. “I’ve seen some people do that.” 

“I guess you can say it sometimes is,” Levi replied, still unsure about the whole wooing ritual thing. “Not everyone would have been that cool about the tentacles, though, keep them secret next time.” 

“What’s wrong with them?” Four of Eren’s tentacles popped out from the water. “They’re pretty common in my village.” 

“Not in mine,” Levi huffed. 

“You were cool with them, though.” 

“I was curious too.” 

Eren grinned, bringing a tentacle up to Levi’s face. “They’re nice, aren’t they? Useful for wooing.” 

“Put that away.” Levi smacked the tentacle. “And what’s up with you and that ‘wooing ritual’ shit?” 

“I told you I was interested in you,” Eren said with a straight face. “I offered you food and we just mated, my intensions are clear.” 

“Wait, you were being serious earlier?” Levi asked, eyes involuntarily widening. 

“Yes.” 

Eren didn’t waste any time replying, he was sure about his intentions. Levi was left speechless, he had never thought Eren was actually courting him, he had never even considered the outcome of their intercourse. He had just gone with the flow, but he had to admit he didn’t regret it. He was curious about Eren, he had always been, and now that he had met him, he was even more interested in him, in his culture, in his straightforward way of living, he just didn’t know how it would technically work between them. 

“I don’t live in this village,” he said. “I live far from here.” 

“Is there an ocean where you live?” Eren asked. 

“No.” 

“Do you have to go back?” 

Did he actually have to go back? Levi didn’t want to, and not only because of Eren, he had never been too keen on his job, he was stressed and everyone there was either an incompetent or a jerk that had driven him nuts every single day for the past ten years. Maybe it was time for a change, it was time to take thing slower and let others deal with that pile of bullshit. 

“No,” he replied, holding Eren’s gaze. “But I have to leave for a while to sort some things out.” 

Eren softly smiled, eyes shining with content. He pressed his forehead on Levi’s and rubbed their noses together. 

“You’ll find me here when you come back.” 

The promise strengthened Levi’s resolve. When he had gone to Hange’s house for a few weeks of well-deserved break, the thought of becoming a supernatural creature’s mate hadn’t even crossed his mind, even now it sounded weird to his own ears, but it didn’t feel wrong. He didn’t know what to expect from the future, his life had been monotonous up until that point, but it was in dire need of a change, and dating someone with one too many limbs was one hell of a change. 

He smiled to himself, wrapping a hand around Eren’s neck before their mouths met in a delicate kiss. The future ahead of him was mysterious and odd, but also thrilling and most definitely sweet.

**Author's Note:**

> Let me know your thoughts on this, and feel free to point out eventual typos or grammatical mistakes, editing fics this long is hell, so I might miss some stuff here and there :)  
> [ Tumblr ](https://talkereritome.tumblr.com/)  
> [ Twitter ](https://twitter.com/exe_rachel) (I'll drop a hint to my next unusual one shot there soon ;))


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